中国物理B ›› 2025, Vol. 34 ›› Issue (1): 10309-010309.doi: 10.1088/1674-1056/ad9ba1

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Improving cutoff frequency estimation via optimized π-pulse sequence

Wang-Sheng Zheng(郑王升)1, Chen-Xia Zhang(张晨霞)2, and Bei-Li Gong(龚贝利)1,†   

  1. 1 School of Electrical Engineering, Guangxi University, Nanning 530004, China;
    2 Faculty of Science and Technology, College of Arts and Sciences of Hubei Normal University, Huangshi 435109, China
  • 收稿日期:2024-08-19 修回日期:2024-10-30 接受日期:2024-12-09 出版日期:2025-01-15 发布日期:2024-12-24
  • 通讯作者: Bei-Li Gong E-mail:aublgong@gxu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 62403150), the Innovation Project of Guangxi Graduate Education (Grant No. YCSW2024129), and the Guangxi Science and Technology Base and Talent Project (Grant No. Guike AD23026208).

Improving cutoff frequency estimation via optimized π-pulse sequence

Wang-Sheng Zheng(郑王升)1, Chen-Xia Zhang(张晨霞)2, and Bei-Li Gong(龚贝利)1,†   

  1. 1 School of Electrical Engineering, Guangxi University, Nanning 530004, China;
    2 Faculty of Science and Technology, College of Arts and Sciences of Hubei Normal University, Huangshi 435109, China
  • Received:2024-08-19 Revised:2024-10-30 Accepted:2024-12-09 Online:2025-01-15 Published:2024-12-24
  • Contact: Bei-Li Gong E-mail:aublgong@gxu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 62403150), the Innovation Project of Guangxi Graduate Education (Grant No. YCSW2024129), and the Guangxi Science and Technology Base and Talent Project (Grant No. Guike AD23026208).

摘要: The cutoff frequency is one of the crucial parameters that characterize the environment. In this paper, we estimate the cutoff frequency of the Ohmic spectral density by applying the $\pi$-pulse sequences (both equidistant and optimized) to a quantum probe coupled to a bosonic environment. To demonstrate the precision of cutoff frequency estimation, we theoretically derive the quantum Fisher information (QFI) and quantum signal-to-noise ratio (QSNR) across sub-Ohmic, Ohmic, and super-Ohmic environments, and investigate their behaviors through numerical examples. The results indicate that, compared to the equidistant $\pi$-pulse sequence, the optimized $\pi$-pulse sequence significantly shortens the time to reach maximum QFI while enhancing the precision of cutoff frequency estimation, particularly in deep sub-Ohmic and deep super-Ohmic environments.

关键词: environment parameters estimation, quantum Fisher information, optimized $\pi$-pulse sequence

Abstract: The cutoff frequency is one of the crucial parameters that characterize the environment. In this paper, we estimate the cutoff frequency of the Ohmic spectral density by applying the $\pi$-pulse sequences (both equidistant and optimized) to a quantum probe coupled to a bosonic environment. To demonstrate the precision of cutoff frequency estimation, we theoretically derive the quantum Fisher information (QFI) and quantum signal-to-noise ratio (QSNR) across sub-Ohmic, Ohmic, and super-Ohmic environments, and investigate their behaviors through numerical examples. The results indicate that, compared to the equidistant $\pi$-pulse sequence, the optimized $\pi$-pulse sequence significantly shortens the time to reach maximum QFI while enhancing the precision of cutoff frequency estimation, particularly in deep sub-Ohmic and deep super-Ohmic environments.

Key words: environment parameters estimation, quantum Fisher information, optimized $\pi$-pulse sequence

中图分类号:  (Decoherence; open systems; quantum statistical methods)

  • 03.65.Yz
03.67.-a (Quantum information) 06.20.-f (Metrology)